针对频率步进雷达目标成像过程中运动参数精确估计及补偿问题,提出了基于脉间和脉内联合调频傅里叶变换的参数估计方法.目标回波信号与本振信号混频后看作线性调频信号,将其作调频傅里叶变换,并在脉组间进行相干累积.通过对调频率的搜索得到目标速度的精确估计,从而实现了低信噪比下目标运动的补偿.由于该方法在调频傅里叶变换过程中,频率维采用了IFFT操作,运算效率较高.计算机仿真结果进一步表明了该方法的有效性和实用性.
To address the problem of accurately estimating and compensating motion parameters in stepped-frequency radar imaging, a method of joint Chirp-Fourier transform based on inter pulse and intra pulse was proposed. After mixing a vibration signal, the target echo can be regarded as a linear FM signal, which can be employed coherent integration after using Chirp- Fourier transform. Through accurate estimation of target velocity by searching the chirp rates, the target motion compensation can be achieved at low SNR. Because of IFFT operation in frequency domain, the algorithm can operate efficiently. The effectiveness and practicality of the method are finally verified by the simulations.